Vacuum-pan.



No. 664.493. Y Patented Dec. 25. I900. 1 4.. & c. mum.

VACUUM PAN.

(Amman medm a. 1899.) a (No Model.) 3 sheets-sheet .HHH

,DZ/ U M 1 3 No. 664,493. Patented Dec. 25, I900.

J. &. C. McNElL.

VACUUM PAN.

(Applicatin filed Nov. 8, 1899.) (No Model.) 3 Sheeta$haet 2.

Patented Dec. 25, I900. J. a c. mum;

V A C U U M P A N (Application filed Nov. 8. 1899.}

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(No Model.)

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UNITED STATES PATENT OF ICE.

JOHN MGNEIL AND CHARLES MONEIIJ, OF GOVAN, SCOTLAND.

VACUUM-PAN.

SPECIFICATION forming part of Letters Patent No. 664,493, dated December 25, 1900.

Application filed November 8, 1899. Serial No. 736,279. (N model.)

To all whom, it may concern;

Be it known that we, JOHN MCNEIL and CHARLES MONEIL, engineers,subjects of the Queen of Great Britain and Ireland, residing at Govan, in the county of Lanark, Scotland, have invented certain new and useful Improvements in Apparatus for Evaporating or Concentrating Saccharine or other Crystallizable Liquids, of which the following isaspecification.

Our said invention comprises certain improvementsin the construction-and operation of apparatus for evaporating or concentrating saccharine or other crystallizable liquids.

Our invention has for its objects the production of abetter quality of sugar, a higher yield of crystals, and-the reduction of time taken to complete a charge. These objects are attained by having rotating heating-surfaces at difierent levels and arranging, during the earlier stage of operation, when the liquid forming a charge is being filled in gradually and before crystallization takes place, to mechanically assist the circulation of the liquid by means of a pump. In this way the whole of the heating-surface is continually in use, thereby effecting a saving in time. In the final stage, when the heating-surfaces are fully immersed by the liquid, their rotation directs the path and causes a constant motion of the crystals through the mother-liquid, thus insuring a more regular and uniform crystal, as well as reducing the risk of the formation of false grain.

In order that our said invention and the manner of performing the same may be prop-' erly understood, we hereunto append three sheets of explanatory drawings, to be hereinafter referred to in describing our improvements.

Figure 1, on Sheet 1 of the drawings, is a side elevation, and Fig. 2, on Sheet 2, a front elevation, of the improved apparatus. Fig. 3, on Sheet 3, is a longitudinal vertical section, and Fig. 4 a transverse vertical section, of a part of the improved apparatus. Fig. 5 is a side elevation, partly in section; and Fig. 6, a transverse Vertical section of details in connection therewith.

In the drawings the same reference-letters are used tomark the same or like parts wherever they are repeated.

In carrying out the invention the evaporating vessel A is made with a semicylindrical upper part, with a curved lower part, and with fiat verticalends A, and it is supported on a framing A fixed to the pillars A The requisite heat for the process of evaporation is applied by means of steam admitted to hollowlens-shaped disks B, (shown on Sheet 3,) of which disks there are three sets on three separate hollow shafts 0, two upper ones and one lower one. The shafts C are arranged in stufiing-box bearings C, fixed or formed on the end plates A of the vessel A, to which are externally connected pipes D, with stopvalves D for admitting steam, similar pipe connections D for drawing ofi water of condensation being provided at the other ends of the shafts. The steam on entering each hollow shaft 0 passes into a compartment D Figs. 5 and 6, formed within the shaft, and then enters by ports D compartments B, formed within each disk by partitions B The water ofcond ensatiou passes out of each diskinto the hollow shaft by ports D and is thereafter discharged by a drain-pipe D ,fixed to the stuffing-gland.

The hollow disks B for each shaft 0 are formed to fit a key or feather E, Fig. 6, fixed to the shaft, and they are firmly jointed together by nuts E, working on a screwedpart ofthe shaft, the nuts pressing the disks as a whole against a shoulder E formed on the shaft. The disks are suitably strengthened with internal ribs B to prevent any tendency -to buckling, while the form of joint between of small tubes J projecting downward for pouring the liquid over the two upper sets of rotating hollow heating-disks B. The juice forming one charge of the vessel Ais filled in gradually,-the lower heating-disks B being first partly immersed and then wholly immersed, the j uice' in rising next gradually immersing the upper two sets of disksB, this mode of working making the evaporating action expeditious. During the first stage of an operation and while the juice or saccharine liquid is being filled in it is made. to circulate, and for this purpose the juice is continually withdrawn from the lower part of the vessel A by a pipe L, (which has the supply-pipe L connected to itat the stop-valve L which is connected to the inlet or suction part of the steam-pu mp K, the pump forcing the liquid up through the pipes J J .1 so as to descend in a number of smalljets upon the hollow rotating heating-disks B. At the same time the liquid is being kept thoroughly mixed by mixers or blades B, fixed to angle-iron bars or frames B helically fixed to the rotating disks B.

In the final stage and after crystallization has taken. place the mechanical circulation of the liquid by means of the pump K is discontinued and the further supply of the liquid for building up the grains is carried on in the usual way.

The circulation and mixing of the liquid in the manner described produces many important and advantageous results, principal among which are that the quantity of first sugars obtainable from a given initial volume of syrup is much increased, the quality of the sugar is also greatly improved, the crystals being more regular, while one of the principal. causes of the formation of false grain is to a great extent eliminated and alsoiviolent ebullition, which causes suspension of liquid particles in the vapor, is prevented. When a charge of the liquid has become sufficiently concentrated, it is emptied from the vessel A through adischarge-valve A, fitted at the bottom of that vessel, into a receptacle (not shown) then placed below to receive it.

The top of the vesselA is connected with. vacuum-producing apparatus by a large pipe M; but before entering this pipe the vapor passes through appliances for separating particles of liquid carried up in suspension in the vapor. The lower end of the pipe M communicates with a box M, Figs. 3 and 4:, occupying a middle part across the space at the upper part of the vessel A, and this box has extending through it and entirely acrossthe vessel A. two tubes M which within the box have openings M at their inner sides, while between the box and the end plates of the vessel. they have openings M at their tops. Below the box M a dished plate M fixed to snugs M on the end plates A, extends angularly across the vessel, but with spaces at the sides for the passage of the vapor, and there arecentral vertical platesM" in the spaces between the box M and the end plates. With this arrangement the rising vapor passing the edges of the dished plate M strikes-the plates M and then finds its way by the'tubes M into the box M, and thence intotheascending pipe M, the effect being, by the baffling of the currents of vapor, to promote the separation from it of suspended particles of liquid. Draining-holes M are formed in the box M" and the tubes M to. allow. the separated particles of liquid collecting in the box and the tubesto fall onto the dished plate M from which the liquid is drained back again into the vessel; overthe'lower end of the plate, and small draining-holesv may also be formed in the plate at suitable parts to further quicken the draining action.

The ascending vapor-pipe M is connected to a jet-condenser-N, supplied with cold water by a pipe Nand connected by a pipe N to an air-pump P. From the bottom of the condenserN a pipe N for the discharge of water descends sufficiently far down to form a Torricellian vacuu m-column. The water,as well as the air, might, however, bewithdrawn from the condenser by means of pumps.

The discharge-pipe P of the air-pump? is bybranch pipes P and stop-valves P connected to the suction-pipe N so that the pump may be made to pumpair through the condenser N and pipe M into the vessel A in order to apply pressure in that vessel when discharging a charge of concentrated juice or liquid from it, a valve N on the pipe N being then closed.

Pressuregages Q, safety-valves. R, and other appliances are provided, as is usual withapparatus for evaporating. or concentrating juices or saccharine liquids.

'What we claim as our invention is-.

1. In apparatus for evaporating or concentrating saccharine or other crystallizable liq: uids, a series. of hollow lens-shaped disks, fixed upon a hollow shaft, with means for admitting steam thereto and withdrawing water of condensation therefrom, in combination with an inclosing casing for the whole, a vacu urn-producing apparatusconnectedwith said casing and bafliin g means atthe top of the easing, comprising a box, tubespassing through the box and extending out from, it across the casing and having ports or openings, acurved plate under the box, and vertical plates at the sides thereof, all substantially as; described.

2. In apparatus for evaporating or concentrating saccharine or other crystallizable liquids, the combination in one vessel of two or more heaters, each comprising a series of hollow lens-shaped disks, a hollow shaft carrying the same, means for admitting steam thereto and withdrawing water of condensation therefrom, in combination with an; in-

closing casing for the whole, means at the top of the casing for baffling the rising vapors and a vacuum-producing apparatus, connected to the casing, substantially as described.

3. In apparatus for evaporating 0r concentrating saccharine or other crystallizable liquids, the combination of an inclosing casing with a hollow shaft, 3. series of hollow lensshaped heating-disks onsaid shaft, frames 1o helieally fixed to the series of disks and blades carried by said frames, all substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

JOHN MCNEIL' CHARLES MCNEIL.

Witnesses:

WM. W. GLAAG, JOHN HOPKIN. 

